Spark-plug shield



Sept. 18 15923. 11,468,539

M. MCCUNE ET AL SPARK PLUG SHIELD Filed Aug. 25 1921 Patented Sept, E8, 1323,

untrue stares PATENT QFFHQEQ MARK MCCUNE AND DAYTON H. RUSSELL, OF MIDDLEPORT, OHIO; SAID RUSSELL AS- SIG-NOR TO SAID MGCUNE.

SPARK-PLUG SHIELD.

Application filed August 25, 1921.

To all whom it may concern:

Be it known that we, MARK MCCUNE and DAYTON H. RUssnLL, citizens of the United States, residing at Middleport, in the county of Meigs and State of Ohio, have invented will enable others skilled in the art to which it appertains to make and use the same.

The object of the invention is to provide a simple and convenient means adapted for use in connection with spark plugs employed in explosive engines for protecting the terminals of spark plugs from deposit of carbon and oil inducin the short circuiting thereof, the device being such as to increase rather than diminish the efliciency of the plug in the matter of i itin the char es and being such as to b appli ed to any of the commercial'forms of spark plugs as a means of connecting them with the motor cylinders, and with this object in view the invention consists in a construction and arrangement of parts of which a preferred embodlment is shown in the accompanying drawings, wherein- Figure 1 is a view in side elevation of the shield applied in theoperative position to an engine motor and spark plug as a means of mounting the latter u on the former,

Figure 2 is a sectiona view of the same,

Figure 3 is a detail view of the shield detached.

The device consists essentially of a cylindrical shell 10 having an outer enlarged member 11 which is interiorlythreaded as shown at 12 and an inner reduced member 13 which is exteriorly threaded as shown at 14, the gages of the threaded portions 12 and 14 being the same and corresponding with the dimensions of the openings provided in the engine cylinders .for the reception of the spark plug casing 15 which in the ordi- Serial No. 495,159.

nary practice is threaded directly into the cylinder wall or head. The enlarged and reduced portions of the casing or shell are connected by the shoulder 16 and in the reduced portion of the shell are arranged the oppositely disposed inwardly directed battle or deflector wings I? and 18 of which the inner edges are spaced apart longitudinally of the shell and substantially in a diametrical plane of the shell to form a relatively restricted passage 19 whereby the mixture or fuel in the cylinder gains access to the terminals 20 of the spark plug.

The use of this shield not only serves as a means of protecting the terminals of the plug but it removes the plug from the interior of the cylinder and the carbon produced in the explosion of the mixture is prevented by the baflies from comin into contact with the spark plug termina s and depositing thereon. Furthermore, the arrangement of the spark plug fully outside of the cylinder prevents the deposit of oil on said terminals and hence eliminates a prolific sort of short circuiting in connection with explosion engines.

What is claimed is:

A spark plug having a shield to project beyond its electrodes and attachable to a cylinder head, the shield being hollow and provided with interior bafiies substantially inclining along intersecting planes and toward the open end of the shield, said bafiles having their free edges substantially straight, in spaced relation and terminating in substantially a common plane extending longitudinally of'the axis of the spark plug to facilitate drainage of oil from the zone of the electrodes;

In testimony whereof we afiix our signatures in presence of two witnesses.

MARK MoCUNE. DAYTON H. RUSSELL. Witnesses:

FRANK FOLEY, C, C. Gmmns. 

